{"id":1673,"date":"2022-05-18T10:49:20","date_gmt":"2022-05-18T05:04:20","guid":{"rendered":"https:\/\/microbenotes.com\/?p=1673"},"modified":"2023-05-17T10:11:32","modified_gmt":"2023-05-17T04:26:32","slug":"methicillin-resistant-staphylococcus-aureus-mrsa","status":"publish","type":"post","link":"https:\/\/microbenotes.com\/methicillin-resistant-staphylococcus-aureus-mrsa\/","title":{"rendered":"Methicillin Resistant Staphylococcus aureus (MRSA)"},"content":{"rendered":"<p><span style=\"color: #000000;\">MRSA is mediated by the mecA gene; which is chromosomally coded. It alters penicillin-binding protein (PBP) present on <em>S. aureus<\/em> cell membrane to PBP-2a:<\/span><\/p>\n<ul>\n<li><span style=\"color: #000000;\">PBP is an essential protein needed for the cell wall synthesis of bacteria. \u03b2 lactam drugs bind and inhibit this protein, thereby inhibiting cell wall synthesis.<\/span><\/li>\n<li><span style=\"color: #000000;\">The altered PBP2a of MRSA strains has less affinity for \u03b2 lactam antibiotics; hence MRSA strains are resistant to all \u03b2 lactam antibiotics.<\/span><\/li>\n<li><span style=\"color: #000000;\">BORSA strains (Borderline Oxacillin resistant <em>S. aureus<\/em>): Occasionally a non-mecA gene-mediated low-level resistance to oxacillin is observed in some strains of <em>S.aureus<\/em>, which is due to hyperproduction of \u03b2 lactamase.<\/span><\/li>\n<li><span style=\"color: #000000;\">There is an increasing trend in the MRSA rates over the last few decades. Though it varies from place to place, overall about 30\u201340% of strains of <em>S. aureus<\/em> are MRSA.<\/span><\/li>\n<li><span style=\"color: #000000;\">MRSA rate in India is 30-40%. It is lowest in Scandinavian countries.<\/span><\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1674\" src=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/12\/Methicillin-Resistant-Staphylococcus-aureus-MRSA.jpg\" alt=\"Methicillin Resistant Staphylococcus aureus (MRSA)\" width=\"800\" height=\"420\" srcset=\"https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/12\/Methicillin-Resistant-Staphylococcus-aureus-MRSA.jpg 800w, https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/12\/Methicillin-Resistant-Staphylococcus-aureus-MRSA-300x158.jpg 300w, https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/12\/Methicillin-Resistant-Staphylococcus-aureus-MRSA-768x403.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0a0a0a;color:#0a0a0a\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #0a0a0a;color:#0a0a0a\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/microbenotes.com\/methicillin-resistant-staphylococcus-aureus-mrsa\/#types-of-mrsa\" title=\"Types of MRSA\">Types of MRSA<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/microbenotes.com\/methicillin-resistant-staphylococcus-aureus-mrsa\/#detection-of-mrsa\" title=\"Detection of MRSA\">Detection of MRSA<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/microbenotes.com\/methicillin-resistant-staphylococcus-aureus-mrsa\/#treatment-of-mrsa\" title=\"Treatment of MRSA\">Treatment of MRSA<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"types-of-mrsa\"><\/span><span style=\"color: #000000;\"><strong>Types of MRSA<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span style=\"color: #000000;\">MRSA are either community or hospital-associated.<\/span><\/p>\n<p><span style=\"color: #000000;\"><strong>Community-associated MRSA (CA-MRSA)<\/strong><\/span><\/p>\n<ul>\n<li><span style=\"color: #000000;\">It is mediated by the mecA gene subtype IV, V, VI.<\/span><\/li>\n<li><span style=\"color: #000000;\">They are usually more virulent and express several toxins such as PV toxin.<\/span><\/li>\n<li><span style=\"color: #000000;\">They cause invasive skin and soft tissue infections such as necrotizing fasciitis.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><strong>Hospital associated MRSA (HA-MRSA)<\/strong><\/span><\/p>\n<ul>\n<li><span style=\"color: #000000;\">It is mediated by the mecA gene subtype I, II, III.<\/span><\/li>\n<li><span style=\"color: #000000;\">They are multidrug-resistant (but their virulence is low).<\/span><\/li>\n<li><span style=\"color: #000000;\">They cause perioperative wound infections in hospitals and nosocomial outbreaks (hospital staff are the major carries).<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><em>Note: CA-MRSA and HA-MRSA terminologies are becoming artificial nowadays; as many CA-MRSA strains have been isolated in hospitals and vice versa.<\/em><\/span><\/p>\n<h2><span class=\"ez-toc-section\" id=\"detection-of-mrsa\"><\/span><span style=\"color: #000000;\"><strong>Detection of MRSA<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><span style=\"color: #000000;\">Antimicrobial susceptibility test: Disk diffusion test can be done by using cefoxitin or oxacillin disks.<\/span>\n<ul>\n<li><span style=\"color: #000000;\">Cefoxitin is the recommended disk to be used.<\/span><\/li>\n<li><span style=\"color: #000000;\">If an oxacillin disk is used, then certain conditions to be maintained such as\u2014using media containing 2\u20134% NaCl, incubation at 30 \u00b0C for 24 hours.<\/span><\/li>\n<\/ul>\n<\/li>\n<li><span style=\"color: #000000;\">Oxacillin screen agar: Adding oxacillin 6 \u03bcg\/ml and NaCl (2\u20134%) to the medium.<\/span><\/li>\n<li><span style=\"color: #000000;\">PCR detecting mecA gene.<\/span><\/li>\n<li><span style=\"color: #000000;\">Latex agglutination test detecting PBP-2a<\/span><\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"treatment-of-mrsa\"><\/span><span style=\"color: #000000;\"><strong>Treatment of MRSA<\/strong><\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><span style=\"color: #000000;\">Vancomycin is the drug of choice for MRSA.<\/span><\/li>\n<li><span style=\"color: #000000;\">Alternate drugs include:<\/span>\n<ul>\n<li><span style=\"color: #000000;\">Teicoplanin, linezolid, quinupristin-dalfopristin, tigecycline, oritavancin.<\/span><\/li>\n<li><span style=\"color: #000000;\">Daptomycin (for endocarditis and complicated skin infections),<\/span><\/li>\n<li><span style=\"color: #000000;\">Mupirocin 2% ointment (for nasal carriers of MRSA).<\/span><\/li>\n<\/ul>\n<\/li>\n<li><span style=\"color: #000000;\">However, even simple orally effective drugs such as tetracycline, erythromycin, or cotrimoxazole may also be effective. These can be indicated in non-serious conditions, caused by CA-MRSA strains if found to be susceptible based on antimicrobial susceptibility report.<\/span><\/li>\n<li><span style=\"color: #000000;\">All \u03b2 lactam drugs should be avoided. However, 5th generation cephalosporins, such as Ceftobiprole, ceftaroline, ceftolozane have shown some activity against MRSA.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><strong>References<\/strong><\/span><\/p>\n<ol>\n<li><span style=\"color: #000000;\">Apurba Sankar Sastry and Sandhya Bhat K (2018). Review of Microbiology and Immunology. Sixth Edition. Jaypee Brothers Medical Publishers (P) Ltd.\u00a0ISBN: 978-93-86322-39-5.<\/span><\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>MRSA is mediated by the mecA gene; which is chromosomally coded. It alters penicillin-binding protein (PBP) present on S. aureus cell membrane to PBP-2a: PBP is an essential protein needed &#8230; <a title=\"Methicillin Resistant Staphylococcus aureus (MRSA)\" class=\"read-more\" href=\"https:\/\/microbenotes.com\/methicillin-resistant-staphylococcus-aureus-mrsa\/\" aria-label=\"Read more about Methicillin Resistant Staphylococcus aureus (MRSA)\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":1674,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6167],"tags":[3328,3329,3333,3326,3325,3327,3331,3332,3330,243],"custom":{"td_video":"","featured_image":"https:\/\/microbenotes.com\/wp-content\/uploads\/2018\/12\/Methicillin-Resistant-Staphylococcus-aureus-MRSA.jpg","author":{"name":"Sagar Aryal","avatar":"https:\/\/secure.gravatar.com\/avatar\/862472ea06500d4318f1ad82addb608e?s=96&d=mm&r=g"},"categories":[{"term_id":6167,"name":"Pharmacology","slug":"pharmacology","term_group":0,"term_taxonomy_id":6167,"taxonomy":"category","description":"<strong>Pharmacology is a discipline that deals with the effects of pharmaceuticals or drugs on living systems, their manufacture, and their chemical properties.<\/strong>\r\n<ul>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Pharmacology is mostly related to studies involving the interactions between the chemicals and living organisms that affect the biochemical functioning of living beings.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The chemicals with medicinal properties are then termed pharmaceuticals.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The concept of medicines has been around for a long time with ancient people using specific plants and species as a form of medicine.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Modern-day pharmacology is involved in the efficient method of drug manufacturing by the use of natural sources and modern technology.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Pharmacology might be confused with pharmacy, but it should be understood that pharmacology deals with the research, discovery, and manufacturing of chemicals with biological effects that affect the cellular and systemic function of the organism.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The field also deals with drug composition and properties, synthesis and drug design, molecular and cellular mechanisms, signal transductions, molecular diagnostic, and biochemistry.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Biochemistry, in particular, is particularly important in pharmacology as the knowledge of the biochemical composition of a living organism is essential in order to assign an appropriate drug for treatment.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Pharmacology focuses on the determination of the mechanism of actions of different groups of drugs which provides a better understanding of the molecular functioning of the body.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The drugs or pharmaceuticals produced from various industrial might be either acquired from natural sources or produced by chemical means.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The most important group of organisms that produce antimicrobials include the actinomycetes, followed by fungi.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">This represents a close relationship between pharmacology studies and mycology and bacteriological studies.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Besides, different technical advances made throughout the years have made it possible for the production of new and improved drugs via biotechnological means.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Pharmacology is further related to other disciplines like clinical medicine for the diagnosis and treatment of diseases.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Other therapeutic agents might also help in decreasing the harmful effects of some diseases like diabetes, HIV, and cancer.<\/span><\/li>\r\n<\/ul>","parent":0,"count":14,"filter":"raw","cat_ID":6167,"category_count":14,"category_description":"<strong>Pharmacology is a discipline that deals with the effects of pharmaceuticals or drugs on living systems, their manufacture, and their chemical properties.<\/strong>\r\n<ul>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Pharmacology is mostly related to studies involving the interactions between the chemicals and living organisms that affect the biochemical functioning of living beings.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The chemicals with medicinal properties are then termed pharmaceuticals.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The concept of medicines has been around for a long time with ancient people using specific plants and species as a form of medicine.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Modern-day pharmacology is involved in the efficient method of drug manufacturing by the use of natural sources and modern technology.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Pharmacology might be confused with pharmacy, but it should be understood that pharmacology deals with the research, discovery, and manufacturing of chemicals with biological effects that affect the cellular and systemic function of the organism.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The field also deals with drug composition and properties, synthesis and drug design, molecular and cellular mechanisms, signal transductions, molecular diagnostic, and biochemistry.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Biochemistry, in particular, is particularly important in pharmacology as the knowledge of the biochemical composition of a living organism is essential in order to assign an appropriate drug for treatment.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Pharmacology focuses on the determination of the mechanism of actions of different groups of drugs which provides a better understanding of the molecular functioning of the body.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The drugs or pharmaceuticals produced from various industrial might be either acquired from natural sources or produced by chemical means.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The most important group of organisms that produce antimicrobials include the actinomycetes, followed by fungi.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">This represents a close relationship between pharmacology studies and mycology and bacteriological studies.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Besides, different technical advances made throughout the years have made it possible for the production of new and improved drugs via biotechnological means.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Pharmacology is further related to other disciplines like clinical medicine for the diagnosis and treatment of diseases.<\/span><\/li>\r\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Other therapeutic agents might also help in decreasing the harmful effects of some diseases like diabetes, HIV, and cancer.<\/span><\/li>\r\n<\/ul>","cat_name":"Pharmacology","category_nicename":"pharmacology","category_parent":0}]},"_links":{"self":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/1673"}],"collection":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/comments?post=1673"}],"version-history":[{"count":0,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/posts\/1673\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media\/1674"}],"wp:attachment":[{"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/media?parent=1673"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/categories?post=1673"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microbenotes.com\/wp-json\/wp\/v2\/tags?post=1673"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}